The present invention concerns a ribbon assembly. Specifically, it concerns a ribbon assembly for printers and other devices which utilize a printing ribbon.
Ribbon assemblies for various printing devices typically comprise a ribbon supply reel, a ribbon take-up reel, and a length of printing ribbon. The ribbon supply reel is usually disposed on one side of a printhead with the ribbon take-up reel being disposed on the opposite side of the printhead. In operation, the ribbon supply reel rotates about a center axis in a direction which allows ribbon to be removed from the ribbon supply reel. Similarly, the ribbon take-up reel rotates about a center axis in a direction which allows the ribbon take-up reel to collect ribbon dispensed by the ribbon supply reel. As the ribbon moves from the ribbon supply reel to the ribbon take-up reel, it passes in front of a printhead which causes a printing medium, such as ink, provided on the ribbon to transfer to a printing surface.
If the printing ribbon is designed for multiple uses, it is often necesary to reverse the direction of rotation of the ribbon supply reel and ribbon take-up reel in order to allow the ribbon to be moved in a reverse direction. This allows the printing ribbon to pass in front of the printhead more than once. Typically, this has been achieved by manually reversing the direction of rotation of the ribbon supply reel and ribbon take-up reel.
Many printing ribbons are thermally operated wherein the printing medium is transferred to the printing surface upon application of thermal energy. A thermal printhead is adapted to supply the thermal energy to the thermal printing ribbon in an appropriate manner. In thermal printing, to assure consistent printing performance, it is desirable to control various operating parameters including the temperature of the printhead, the speed of printing, the speed with which the print ribbon passes in front of the printhead, and the like.
With known ribbon assemblies and printheads, these operating parameters have typically been set manually and adjusted as printing conditions change. For instance, if a first thermal printing ribbon is replaced with a second thermal printing ribbon, it may be necessary to manually adjust the thermal energy output of the printhead in order to assure consistent printing.